Today, mobile TV services and other content distribution services are delivered over existing networks using so-called unicast delivery. Unicast delivery means that each user terminal gets its own unique data connection for accessing one or more content channels. One drawback of this approach is that it does not scale satisfactorily if an increasing number of user terminals is starting to use a particular service.
An alternative to unicast delivery is broadcast delivery. In a broadcast scenario each content channel is distributed to all user terminals simultaneously. In this way, the number of data connections can be significantly reduced because the number of required data connections only depends on the number of distributed content channels and no longer on the number of active user terminals.
Although broadcasting reduces the number of required data connections, it is important to understand that broadcasting is not always the most efficient way of delivering content channels. In a typical broadcast scenario, content channels are transmitted even if there are no user terminals listening to them since the broadcasting system does not have any knowledge about who is listening to a channel and who is not. Furthermore, the transmission power of a broadcast bearer in a radio cell cannot be adapted to the receive conditions of different user terminals. Instead it must be sufficiently high such that even user terminals with bad coverage can still receive a good enough signal.
Compared to broadcast, unicast delivery has the advantage that network resources are only allocated if requested. Furthermore, with unicast delivery a base station can optimize its transmission power for each user terminal individually such that user terminals closer to the base station require less power than user terminals further away.
In addition to broadcast and unicast, multicast is a third transport alternative. Multicast adds group management capabilities to broadcast. However, support for multicast requires an increased implementation effort. Multicast support can for example be provided via the Multimedia Broadcast Multicast Service (MBMS).
Conventional TV content channels are typically located for a long time on one physical transport bearer. This means that a frequency or a location in a multiplex scheme is permanently assigned to one content channel. Today's TV does not implement any function to automatically re-configure the content transmission parameters. However, there is also no need to offer a TV channel re-location functionality, since anyhow all transport channels are broadcast transport channels.
There is a need for a content distribution/reception technique that allows to make use of the combined advantages of different bearer types.